HIGH IDLE

I have a 2005 Suzuki Forenza. The engine light is on and the car idles high (in park between 2000 - 2500 RPM, in drive about 1000-1500). I can hear what sounds like a vacuum line disconnected, but cannot locate one. I took it to the shop and they are saying that it is the EGR valve. I have put a new EGR valve on the car but the problem persist. Also when driving, if I come to somewhat of an abrupt stop, the car jerk as if the transmission is changing gears. Could the problem be the AIC? Would this cause the engine light to come on as well?